The present invention relates to semiconductor packages and, more particularly to, a vertical surface mounted semiconductor package which is firmly mounted vertically on a printed circuit board (PCB) by forming a protrusion on its body.
Recently, according to the trends toward higher density, higher capacity, faster signal processing speed, increasing power consumption, multi-function, and higher packing density, the importance of semiconductor chip package design is growing. Along with higher density and higher capacity of semiconductor chips and memory devices, the number of input and output pin leads is increased, so a fine pitch between the leads is required. Also, in order to dissipate a large amount of heat generated in the semiconductor chip according to the increase of operating speed and power consumption, an additional heat sink is required in the semiconductor package or the package body must be made of materials having a high thermal conductivity. With the multi-function of the semiconductor chip, semiconductor packages with a variety of functions are required. In addition, according to demands for high-density mounting of the semiconductor chips, investigation of stacked mounting of the semiconductor packages or direct mounting of the semiconductor chips into the PCB is proceeding.
In general, semiconductor chips (e.g., IC and LSI) are sealed in packages and mounted on the PCB. In the case of a standard semiconductor chip package, the semiconductor chip is loaded on a metal die pad for heat sink purposes. Then the electrode pads on the semiconductor chip are connected with leads for connection with external circuits by bonding wires. A package body made of epoxy molding compound (EMC) is formed to protect the semiconductor chip and the bonding wires. A dual in line package (DIP) type in which the leads extend from opposing sides of the package and a quad flat package (QFP) type in which the leads extend from all four peripheral sides of the package are very common. Since the QFP can form more lead connections than the DIP, it enhances the mounting density on the PCB.
In order to further enhance the mounting density of the chip packages, a vertical package (VPAK) and a vertical surface mounted package (VSMP) that occupy a small area due to vertical mounting on the PCB are being investigated.
FIGS. 1 and 2 show a conventional VPAK 10.
A plurality of leads 14 which are connected to the PCB (not shown) protrude from one side of a rectangular package body 12 in which a semiconductor chip (not shown) is mounted. The leads 14 are all aligned in the same direction. Also, support portions 16 protrude at both ends of the side of the package body 12 from which the leads 14 protrude. The support portions 16 are formed of EMC like the package body 12 and extend from the package body 12 farther than the leads 14. Also, the support portions 16 each have a hanging jaw 18 in a middle part to protect the bent leads 14.
As shown in FIG. 10, the ends of the support portions 16 are inserted into holes 42 formed on the PCB so that the VPAK 10 is firmly supported. The hanging jaw 18 is adhered onto an upper part of the hole 42 to thereby prevent the leads 14 from being deformed.
FIGS. 3 to 5 show a conventional VSMP 20. A plurality of leads 24 which are electrically connected to the PCB (not shown) protrude from one side of a rectangular package body 22 on which the semiconductor chip (not shown) is mounted. The leads 24 are bent in the same direction. A pair of support portions 26 are formed at both ends of the side of the package body 22 having leads 24 extending therefrom and are bent in both directions to support the package body 22. The support portions 26 are made of metal, are longer than the leads 24, and are aligned with the leads 24. The VSMP 20 is adhered on the PCB 40 by soldering so it is firmly supported, thereby preventing the leads 24 from being deformed due to external force.
In the conventional VPAK 10, however, the mounting process is complicated since the holes 42 into which the support portions 16 are inserted must be formed separately to mount the VPAK 10 on the PCB 40. Also, in the VSMP 20, the leads 24 are susceptible to deformation when a thin lead frame is used.